What Is O11y

O11y, shorthand for Observability - O + 11 letters + y :-)

Observability is the ability to understand the internal state of a system by examining only the data it outputs.

Three Pillars

Metrics

Quantitative measurements collected over time. Useful for dashboards, alerts, and trend analysis.

Traces

Traces show the journey of a request through a system. Comprised of spans, which represent operations. Useful for understanding latency, bottlenecks, and dependencies.

Logs

Text records of events in an application. Structured logs (e.g., JSON) are preferred. Critical for debugging and incident analysis.